KR100333171B1 - N-alkyl-N'-aryl-P-phenylenediamine useful as a modifier for epoxy resins - Google Patents

Abstract

The present invention, when added at 2.5 to 12.5% by weight, based on the total weight of the epoxy resin and component (b), after curing the epoxy resin cured in terms of physical properties such as strength, stiffness, toughness and heating / wetting properties. It relates to N-alkyl-N'-aryl-p-phenylenediamine which shows a significant increase relative to the properties of unmodified epoxy resins.

Description

N-alkyl-N'-aryl-p-phenylenediamine useful as modifier for epoxy resins

The present invention relates to N-alkyl-N'-aryl-p-phenylenediamines as modifiers for epoxy resins made from cured modified resins and exhibiting significantly enhanced physical properties.

Incidentally, it has long been an object in the epoxy resin field to improve physical strength, such as the strength and modulus of the cured epoxy resin without increasing its brittleness.

U.S. Patent No. 4,480,082 discloses mono- or di-epoxides and aromatic amides such as phenyl glycidyl ether or addition products of vinylcyclohexene dioxide and 4-hydroxyacetanilide as reinforcing agents in amine cured epoxy resins. It is known to use reaction products.

U.S. Patent No. 4,739,028 discloses the reaction of diepoxides and aromatic polyhydroxy compounds in which one oxirane group is less reactive than another, such as vinylcyclohexene dioxide and resorcinol as reinforcing agent in amine cured epoxy resins. The use of the product is described.

US Pat. No. 4,816,533 describes the use of reaction products of asymmetric diepoxides and aromatic amines such as aniline and vinylcyclohexene as reinforcing agents for amine cured epoxy resins.

US Pat. No. 4,851,484 describes the use of m-aminoacetanilide and reaction products of carboxylic acids such as maleic acid, substituted aromatic amines and carboxylic anhydrides such as nad methyl anhydride as reinforcing agents for amine cured epoxy resins.

U.S. Patent No. 4,767,809 discloses the use of a substituted phenylene diamine compound in a crosslinked rubber composition, such as the compound N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine of the present invention. high resistance to growth). It is described or not shown that such substituted phenylenediamine compounds provide enhanced strength and modulus properties for amine cured epoxy resins.

N-alkyl-N'-aryl-p-phenylenediamines, in particular N-isopropyl-N'-phenyl-p-phenylenediamine, are antioxidants, ozone crackers and stabilizers for elastomers, rubbers and thermoplastics. It is widely used. Their use as modifiers to enhance the physical properties of cured epoxy resins comprising such modifiers is not known.

The present invention (a) an epoxy resin; (b) an effective amount of a curing agent; And (c) from 2.5 to 12.5% by weight of a compound of formula (I), based on the total weight of the epoxy resin and component (b), of a curable modified epoxy resin composition having enhanced physical properties after curing. :

Wherein E and T are independently alkyl of 5 to 12 carbon atoms, cycloalkyl of 5 to 8 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, aryl of 6 to 10 carbon atoms or alkyl of 1 to 4 carbon atoms Aryl substituted with 1 or 2.

Preferably, E is alkyl of 5 to 12 carbon atoms or aryl of 6 to 10 carbon atoms; Most preferably aryl of 6 to 10 carbon atoms; Especially phenyl.

Preferably, T is alkyl of 6 to 12 carbon atoms; Alkyl of 6 to 8 carbon atoms; In particular 1,3-dimethylbutyl or 1,4-dimethylpentyl; More particularly 1,3-dimethylbutyl.

Preferably the amount of component (c) is 4 to 11% by weight, based on the total weight of the epoxy resin and component (b); Most preferably, it is 5 to 10 weight%.

When E and T are alkyl, alkyl is straight or branched chain alkyl such as n-amyl, secondary-amyl, isoamyl, n-hexyl, secondary-hexyl, isohexyl, 1,3-dimethylbutyl, 1,4 -Dimethylpentyl, heptyl, 2-ethylhexyl, isooctyl, tert-octyl, nonyl, n-decyl, isodecyl, lauryl, isododecyl or tertiary dodecyl; When cycloalkyl, they are, for example, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl; When phenylalkyl, they are, for example, benzyl, α-methylbenzyl, α, α-dimethylbenzyl; When aryl or aryl to be substituted, they are, for example, phenyl, naphthyl, tolyl or xylyl.

Epoxy resins useful as component (a) in the present invention are conventional epoxy resins containing on average one or more epoxy groups per molecule, such as polyhydric phenols, aliphatic or cycloaliphatic alcohols such as bisphenol A, bisphenol F, resorcinol, dihydroxy Cidiphenyl, 4,4'-dihydroxydiphenyl sulfone, glycidyl ether of dihydroxynaphthalene and a condensation product of formaldehyde with phenol or cresol. Other epoxy resins include glycidyl ethers of halogenated mono-, di- or polynuclear phenols; Glycidylated amines, aminophenols and amides; Glycidylated polyacids; And a cycloaliphatic epoxy resin having an epoxy group attached to a cyclohexane or cyclopentane ring. Also contemplated are mixtures of polyepoxides and mixtures of monoepoxides with polyepoxides as described above.

Some specific examples of such epoxy resins include diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F; Diglycidyl ethers of hydroquinone, resorcinol, catechol, 2,5-dihydroxynaphthalene or 9,9-bis (4-hydroxyphenyl) fluorene; Tetraglycidyl ethers of 3,3,3 ', 3'-tetramethyl-1,1'-spirobisindane-5,5', 6,6'-tetraol; Methylenedianiline, m-phenylenediamine, 1,4-di (α, α-dimethyl-4-aminobenzyl) benzene, 1,4-di (α, α-dimethyl-3-methyl-4-aminobenzyl) Tetraglycidyl derivatives of benzene or 3,3'-diethyl-4,4'-diaminophenylmethane; Triglycidyl derivatives of 4-aminophenol or 3-methyl-4-aminophenol; Diglycidyl derivatives of aniline; Di (2-glycidyloxy-1-naphthyl) methane, di (2,5-diglycidyloxy-1-naphthyl) methane or 2-glycidyloxy-1-naphthyl-2 ', An epoxy resin based on a glycidyl derivative of 5'-diglycidyloxy-1'-naphthylmethane.

Preferred epoxy resins are liquid polyglycidyl ethers of bisphenol A and bisphenol F having an epoxy equivalent of 160 to 200.

Curing agents of component (b) are aliphatic, aromatic or cycloaliphatic di- or polyamines such as diethylenetriamine, N-aminoethylpiperazine, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino Diphenyl sulfone, diethyldiaminotoluene, dicyandiamide or guanidine; Polycarboxylic acid anhydrides such as phthalic anhydride or trimellitic anhydride; Catalytic curing agents such as tertiary amines, imidazoles or complexes of boron trifluoride; Di- and polyfunctional phenols such as bisphenol A, tetrabromobisphenol A, or phenol or cresol novolak resins.

Some preferred embodiments of component (b) include 3,3'-diaminodiphenyl sulfone; 4,4'-diaminodiphenyl sulfone; 4,4'-methylenedianiline; 4,4'-methylenebis (2-chloroaniline); 4,4'-methylenebis (2-methylaniline); m-phenylenediamine; p-phenylenediamine; 1,4-di (α, α-dimethyl-4-aminobenzyl) benzene, 1,4-di (α, α-dimethyl-3-methyl-4-aminobenzyl) benzene; 3,3'-diethyl-4,4'-diaminodiphenylmethane; 2,2'-dimethyl-5,5'-diaminodiphenyl sulfone; 1,8-diaminonaphthalene; 4,4'-methylenebis (2,6-diethylaniline); 2,2-dimethyl-2,3-dihydropyrimidine; 1- (4-aminophenyl) -1,3,3-trimethyl-5 (6) -aminoindane; Trimethylene bis (4-aminobenzoate), diethylenetriamine, N-aminoethylpiperazine, 4,4'-diaminodicyclohexylmethane, 2,4-diethyl-3,5-diaminotoluene, Phthalic anhydride, trimellitic anhydride; Complexes of tertiary amines, imidazoles or boron trifluoride; Bisphenol A; Tetrabromobisphenol A, or phenol or cresol novolak resin; And especially 3,3'-diaminodiphenyl sulfone, 2,4-diethyl-3,5-diaminotoluene, 3,3'-diaminodiphenyl sulfone and 3,4-epoxy-cyclohexylmethyl 3, Addition product of 4-epoxycyclohexane carboxylate, diethylenetriamine, 3,3'-dimethyl-4,4'-diaminodicyclohexane or imidazole catalyst 3- (2-methylimidazole-1- (1) propionic acid; More particularly 2,4-diethyl-3,5-diaminotoluene.

Except for the catalytic curing agent, all of the curing agents of component (b) are used in an amount of 50 to 150% of a chemical theoretical amount in which the ratio of active hydrogen and epoxy groups is 1: 1. Thus, the effective amount of the curing agent of component (b) is -NH-0.5 to 1.5 equivalents per epoxy residue equivalent.

Catalytic curing agents are used in amounts of 0.5 to 15% by weight of component (a).

Epoxy resins modified with the present compounds of general formula (I) are particularly useful in the production of composites, adhesives, molding compounds, mold encapsulation materials, coatings and other various applications in which epoxy resins are particularly suitable. The composition of the present invention is particularly effective for producing a matrix resin for an automated process of producing a composite, which is included in filament winding and the like.

When the modifier of formula (I) is incorporated into the epoxy resin, the cured epoxy resin has enhanced properties in physical properties, in particular in elastic modulus, strength and stretching surface. This property increases from 10 to 30% with increasing toughness up to 80%. This phenomenon is unusual because an increase in elastic modulus usually involves a decrease in stretching and toughness. The retention of elastic modulus and strength properties is also improved under high temperature / wetting conditions.

The process characteristics of the epoxy resin composition of the present invention are also improved by the modifier of formula (I) due to their low viscosity (about 50 cps at 60 ° C.) and reactivity.

The compound of general formula (I) is a known compound. Some are commercially available such as N-1,3- dimethylbutyl -N'- phenyl -p- phenylene diamine ^{(FLEXZONE? 7L, Uniroyal Chemical)} . Other compounds of formula (I) can be prepared by conventional methods from commercially available starting materials.

The following examples are presented for the purpose of illustrating the invention only and are not intended to limit the scope or nature of the invention.

Preparation of the epoxy resin composition of this invention includes simply mixing three components (a), (b), and (c) at the temperature of 50-120 degreeC.

The test method used in the examples is as follows:

Mechanical Properties—Bend and tensile specimens are tested for ASTM D790 and ASTM D638 respectively. Calculate the energy E _b for the brake as the area under the load / travel curve. Toughness for tensile and flexural tests is calculated as E _b / (L xbxa) (where bxa is the cross section of the specimen, L is the gauge length of the tensile test, and span is a 3-point bending). Fracture toughness is measured by performing a 3-point notch bending test with a span of 2.54 mm and a notch depth of 1.27 mm according to ASTM STP410.

Dynamic Mechanical Analysis (DMA)-Specimens measuring 3 mm x 12.5 mm x 30 mm are tested in a double clamp beam mode oscillating in the temperature range of 30 ° to 225 ° C at a heating rate of 10 ° C / min.

Wet Properties—Measure samples immediately after 48 hours of immersion in boiling water for wobble and DMA tests.

Example 1

The epoxy resin, which is a diglycidyl ether of bisphenol A with an epoxy equivalent of 185, was cured with a curing agent 2,4-diethyl-3,5-diaminotoluene with a ratio of epoxy resin to amine curing agent at 1: 1. The curing cycle was 1 hour at 120 ° C., then 1 hour at 150 ° C. and finally 2 hours at 180 ° C., based on the total weight of the epoxy resin and the curing agent, N-1,3-dimethylbutyl-N ′. Comparison is made with the same composition except that it is modified with 10% by weight of -phenyl-p-phenylenediamine.

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin.

Example 2

The epoxy resin, which is a diglycidyl ether of bisphenol F having an epoxy equivalent of 160, is cured and cured with 2,4-diethyl-3,5-diaminotoluene with a ratio of epoxy resin to amine curing agent of 1: 1.2. The cycle was 1 hour at 120 ° C., then 1 hour at 150 ° C. and finally 2 hours at 180 ° C., based on the total weight of the epoxy resin and the curing agent, N-1,3-dimethylbutyl-N'- Comparison is made with the same composition except that it is modified with 10% by weight of phenyl-p-phenylenediamine.

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin.

Example 3

The epoxy resin which is the diglycidyl ether of bisphenol A of epoxy equivalent 185, 3: 3'- diamino diphenyl sulfone and 3, 4- epoxycyclohexyl by making ratio of epoxy resin to amine hardener 1: 0.87 N-1,3-dimethylbutyl-N, based on the total weight of the epoxy resin and the curing agent, cured with a curing agent which is an addition product of methyl 3,4-epoxycyclohexanecarboxylate and the curing cycle was 4 hours at 180 ° C. It is compared with the same composition except that it is modified with 10% by weight of '-phenyl-p-phenylenediamine.

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin.

Example 4

When using the epoxy system described in Example 3, the amount of component (c), N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine, based on the total weight of the epoxy resin and the curing agent Vary from 0 to 20% by weight. The results relating to the yaw modulus, strength and the wet and dry T _g are given in the table below.

From these data, in order to maximize the properties, the appropriate amount of the composition component (c) of the present invention is about 10% by weight based on the total weight of the epoxy resin and the curing agent.

Example 5

Epoxy resin, a diglycidyl ether of bisphenol A with an epoxy equivalent of 185, was cured with a curing agent diethylenetriamine with a ratio of epoxy resin to amine curing agent at 1: 1, and the curing cycle was allowed to stand at room temperature for 24 hours. 10% by weight of N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine based on the total weight of the epoxy resin and the curing agent at 2 hours at 80 ° C and finally at 2 hours at 100 ° C. Compare with the same composition except that it is modified with

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin.

Example 6

An epoxy resin which is a diglycidyl ether of bisphenol A having an epoxy equivalent of 185 is a hardener 3,3'-dimethyl-4,4'-diaminocyclohexane with a ratio of epoxy resin to amine curing agent at 1: 1. Curing and curing cycle 1 hour at 80 ° C., then 1 hour at 100 ° C. and finally 4 hours at 150 ° C., based on the total weight of epoxy resin and curing agent, N-1,3-dimethylbutyl Comparison is made with the same composition except that it is modified with 10% by weight of -N'-phenyl-p-phenylenediamine.

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin.

Example 7

The epoxy resin which is a diglycidyl ether of bisphenol A with an epoxy equivalent of 185 is cured with an imidazole catalyst which is 3- (2-methylimidazol-1-yl) -propionic acid. The catalyst is dissolved in triethanolamine at 50% by weight and 5 parts by weight of the solution are used per 100 parts by weight of the epoxy resin. The curing cycle is 30 minutes at 130 ° C. Based on the total weight of the epoxy resin and the curing agent, the properties of the same composition and cured resin were modified except that 10% by weight of N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine was modified. Compare.

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin.

Example 8

The epoxy resin, which is a diglycidyl ether of bisphenol A with an epoxy equivalent of 185, was cured with a curing agent 2,4-diethyl-3,5-diaminotoluene with a ratio of epoxy resin to amine curing agent at 1: 1. The curing cycle was 1 hour at 120 ° C., then 1 hour at 150 ° C. and finally 2 hours at 180 ° C., based on the total weight of the epoxy resin and the curing agent, N, N′-bis (1,4 -Dimethylpentyl) -p-phenylenediamine 10% by weight, except that it is compared with the same composition.

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin.

Example 9

N, N, N ', N'-tetraglycidyl-3,3'-diethyl-4,4'-diaminodiphenylmethane having an epoxy equivalent of 125 is 25% by weight of bisphenol F having an epoxy equivalent of 160 The epoxy resin mixture comprising 75% by weight of diglycidyl ether was cured with 3,3'-diaminodiphenyl sulfone with a ratio of amino group to epoxy group of 0.87: 1, and the curing cycle was 4 hours at 180 ° C. The composition is compared with the same composition except for the modification of 10% by weight of N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine based on the total weight of the epoxy resin and the curing agent.

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin. This modification results in a unique effect of simultaneously increasing the highly desirable properties of heating / wetting modulus and fracture toughness (twice the control).

Example 10

N, N, N ', N'-tetraglycidyl-3,3'-diethyl-4,4'-diaminodiphenylmethane having an epoxy equivalent of 125 and a bisphenol F having an epoxy equivalent of 160 The epoxy resin mixture comprising 75% by weight of diglycidyl ether was cured with 3,3'-diaminodiphenyl sulfone with a ratio of amino group to epoxy group of 0.87: 1, and the curing cycle was 4 hours at 180 ° C. The composition is compared with the same composition except for the modification of 5% by weight of N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine based on the total weight of the epoxy resin and the curing agent.

Physical properties of the cured 2 resin are shown in the table below.

It is clear that the cured modified epoxy resin exhibits much better physical properties than the cured unmodified control epoxy resin. This modification results in a unique effect of simultaneously increasing both highly desirable properties of heating / wetting modulus and fracture toughness (twice the control).

The results given in Examples 1 to 10 are based on epoxy resins comprising from 5 to 10% by weight, based on the epoxy weight of N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine or related modifiers. Cured products having both high strength, toughness, and heat / wet performance properties are produced to include resins suitable for various embodiments, including tough matrix resins for transfer molding. At this time, the combination of high toughness and low resin viscosity in the cured resin has a low yield stress, such as electronic encapsulation and electrical conduction such as encapsulation of semiconductor, which improves stress relief treatment without cracking, molding tools, coating solution, adhesive and Required for laminating In a multilayer printed circuit board, perforation is improved by a toughening effect.

Claims (19)

(a) an epoxy resin; (b) effective amount of curing agent; And (c) from 2.5 to 12.5% by weight of a compound of formula (I), based on the weight of the epoxy resin, a curable modified epoxy resin composition having enhanced physical properties after curing; Wherein E and T are independently alkyl of 5 to 12 carbon atoms, cycloalkyl of 5 to 8 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, aryl of 6 to 10 carbon atoms or alkyl of 1 to 4 carbon atoms Aryl substituted with 1 or 2. The method of claim 1, wherein the epoxy resin of component (a) comprises polyhydric phenol, aliphatic and cycloaliphatic alcohol, 4,4'-dihydroxydiphenyl sulfone, glycidyl ether of dihydroxynaphthalene; Condensation products of formaldehyde with phenol and cresol; Glycidyl ethers of halogenated mono-, di- and polynuclear phenols; Glycidylated amines, aminophenols and amides; Glycidylated polyacids; Cycloaliphatic epoxy resins having an epoxy group attached to a cyclohexane and a cyclopentane ring; And mixtures thereof. The method of claim 1, wherein the epoxy resin of component (a) is diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, hydroquinone, resorcinol, catechol, 2,5-dihydroxynaphthalene or Diglycidyl ether of 9,9-bis (4-hydroxyphenyl) fluorene; Tetraglycidyl ethers of 3,3,3 ', 3'-tetramethyl-1,1'-spirobisindane-5,5', 6,6'-tetraol; Methylenedianiline, m-phenylenediamine, 1,4-di (α, α-dimethyl-4-aminobenzyl) benzene, 1,4-di (α, α-dimethyl-3-methyl-4-aminobenzyl) Tetraglycidyl derivatives of benzene or 3,3'-diethyl-4,4'-diaminophenylmethane; Triglycidyl derivatives of 4-aminophenol or 3-methyl-4-aminophenol; Diglycidyl derivatives of aniline; Di (2-glycidyloxy-1-naphthyl) methane, di (2,5-diglycidyloxy-1-naphthyl) methane or 2-glycidyloxy-1-naphthyl-2 ', 5'-diglycidyloxy-1'-naphthylmethane. The epoxy resin of component (a) is diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, 3,3'-diethyl-4,4'-diaminodiphenylmethane. The composition is a tetraglycidyl derivative or a mixture thereof. The compound of claim 1 wherein component (b) is selected from aliphatic, aromatic or cycloaliphatic di- or polyamines; Dicyandiamide; Guanidine; Polycarboxylic acid anhydrides; Catalytic curing agents; Or a bifunctional or polyfunctional phenol. A compound according to claim 1, wherein component (b) comprises 3,3'-diaminodiphenyl sulfone; 4,4'-diaminodiphenyl sulfone; 4,4'-methylenedianiline; 4,4'-methylenebis (2-chloroaniline); 4,4'-methylenebis (2-methylaniline); m-phenylenediamine; p-phenylenediamine; 1,4-di (α, α-dimethyl-4-aminobenzyl) benzene, 1,4-di (α, α-dimethyl-3-methyl-4-aminobenzyl) benzene; 3,3'-diethyl-4,4'-diaminodiphenylmethane; 2,2'-dimethyl-5,5'-diaminodiphenyl sulfone; 1,8-diaminonaphthalene; 4,4'-methylenebis (2,6-diethylaniline); 2,2-dimethyl-2,3'-dihydropyrimidine; 1- (4-aminophenyl) -1,3,3-trimethyl-5 (6) -aminoindane; Trimethylene bis (4-aminobenzoate), diethylenetriamine, N-aminoethylpiperazine, 4,4'-diaminodicyclohexylmethane, 2,4-diethyl-3,5-diaminotoluene, Phthalic anhydride, trimellitic anhydride; Complexes of tertiary amines, imidazoles or boron trifluoride; The composition is bisphenol A, tetrabromobisphenol A, or a phenol or cresol novolak resin. A compound according to claim 1, wherein component (b) is 3,3'-diaminodiphenyl sulfone, 2,4-diethyl-3,5-diaminotoluene, 3,3'-diaminodiphenyl sulfone and 3, Addition product of 4-epoxy-cyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, diethylenetriamine, 3,3'-dimethyl-4,4'-diaminodicyclohexane or 3- (2-methyl Imidazol-1-yl) propionic acid. 8. The composition of claim 7, wherein component (b) is 2,4-diethyl-3,5-diaminotoluene. The composition of claim 1, wherein in the compound of formula (I) of component (c), E is alkyl of 5 to 12 carbon atoms or aryl of 6 to 10 carbon atoms. 10. The composition of claim 9, wherein E is aryl of 6 to 10 carbon atoms. The composition of claim 10, wherein E is phenyl. The composition of claim 1 wherein in the compound of formula (I) of component (c), T is alkyl of 6 to 12 carbon atoms. 13. The composition of claim 12, wherein T is alkyl of 6 to 8 carbon atoms. The composition of claim 13, wherein T is 1,3-dimethylbutyl or 1,4-dimethylpentyl. A compound according to claim 1, wherein component (c) is N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine or N, N'-bis (1,4-dimethylpentyl) -p-phenylene The composition is a diamine. The composition of claim 1 wherein the amount of component (c) is 4 to 11 weight percent based on the total weight of the epoxy resin and component (b). The composition of claim 16 wherein the amount of component (c) is from 5 to 10% by weight, based on the weight of the epoxy resin and component (b). A process for preparing a composition according to claim 1 comprising mixing components (a), (b) and (c) at a temperature of 50 to 120 ° C. Composites, laminates, adhesives, encapsulated devices, shaped articles or coatings prepared from the composition according to claim 1.